1. Field of the Invention
The present invention relates to a vibration device for use in a camera body including a lens, and to a camera.
2. Description of the Related Art
An on-vehicle camera and a camera installed outdoors are exposed to rain. For this reason, a cover made of glass or a transparent plastic material is provided on a front side of a lens. However, if water drops adhere to the cover, the view of the camera becomes unclear. Moreover, images sometimes cannot be taken accurately.
Japanese Unexamined Patent Application Publication No. 2012-138768 discloses a dome-shaped cover for use in such an application. A cylindrical part is connected to the dome-shaped cover, and a piezoelectric ceramic vibrator is mounted in the cylindrical part. By vibrating the piezoelectric ceramic vibrator, the cylindrical part and the dome-shaped cover are vibrated. Water drops adhering to a surface of the dome-shaped cover are thereby removed.
On the other hand, Japanese Unexamined Patent Application Publication No. 2007-82062 discloses a structure in which an ultrasonic transducer, an adhesive layer, and an external lens are arranged on a front side of a camera body. The external lens is vibrated by driving the ultrasonic transducer. Water drops are thereby removed.
To remove water drops in Japanese Unexamined Patent Application Publication No. 2012-138768 and Japanese Unexamined Patent Application Publication No. 2007-82062, it is necessary to greatly vibrate the dome-shaped cover and the external lens. That is, it is necessary to generate a large vibration in the piezoelectric ceramic vibrator and the ultrasonic transducer in the structures of Japanese Unexamined Patent Application Publication No. 2012-138768 and Japanese Unexamined Patent Application Publication No. 2007-82062. For this reason, a large stress is applied to the piezoelectric ceramic vibrator and the ultrasonic transducer. As such, cracks may occur in the piezoelectric ceramic vibrator and the ultrasonic transducer during use and may cause functional failure. In addition, it is required to remove not only the water drops but also, for example, a solution other than water, such as ethanol, a water solution in which, for example, salt or an antifreezing agent (calcium chloride) is dissolved, droplets, such as muddy water, containing impurities that are not dissolved in water, or a colloidal solution such as coffee.